Be cautious with low-shelving boosts if your monitoring system (including your room as well as your speakers) struggles to convey information below 40-50Hz. Lots of rubbish like traffic rumble and mechanical thuds can be lurking at the spectrum's low extremes, and you don't want to boost this. If you must apply a shelving boost, also use a 20-30Hz high-pass filter for safety. LF shelving filters also continue acting, to some degree well beyond their specified frequency, so if you find you've collected excess low mid-range baggage while trying to boost the true low end, a compensatory peaking cut at 200-400Hz may be in order.